MONDAY, Dec. 29, 2014 (HealthDay News) -- Anorexia is typically associated with women, but a new report finds that men -- especially men obsessed with muscularity -- can develop the eating disorder, too.

The Canadian researchers noted that an estimated 10 percent or more of anorexia patients are thought to be male, though the actual number may be significantly higher. There was also a slightly larger proportion of gays with anorexia than is seen in women with the illness, the study found.

"We know that anorexia does touch more women, but even though many parents, and even medical professionals, don't realize it, it's also among boys and men," said study lead author Dominique Meilleur, an associate professor of psychology who studies adolescence and eating disorders at the University of Montreal.

"The problem is that the subject hasn't been studied enough among men, so we don't even know if the symptoms we use to measure for anorexia are appropriate for men, because they are mainly developed for women," Meilleur added.

One big gender difference: While female patients tend to place an excessive focus on food control and/or food rejection, male patients tend to focus more on excessive exercise and muscle gain.

In their research, Meilleur's team focused on 24 studies conducted in English or French between 1994 and 2011. Together, the studies included 279 male anorexia patients between ages 11 and 36 (at an average age of 18). All had been hospitalized for severe malnutrition.

In some but not all of the studies, patient characteristics were noted. Viewpoints on weight were collected from about a quarter of the male patients.

Among those patients, nearly half said they were afraid of gaining weight and becoming fat and about the same number said they were unhappy with their current weight and wanted to lose more.

About a third of the men and boys studied were asked about their sense of "body image." Nearly two-thirds of them said that their dissatisfaction with their body stemmed from a desire for increased muscle mass and lower body fat.

Sexual preference was noted for roughly a fifth of the patients, and 13 percent identified as homosexual -- a larger number than is seen in the spectrum of women with anorexia, the authors said.

Other mental issues also often played a role. Meilleur's team were able to ascertain data on mental health for about a quarter of the men and boys studied, and they found that more than one in four struggled with depression, while nearly 18 percent suffered from some form of obsessive disorder.

Substance abuse was seen among more than 11 percent.

All of this opens up new questions about the causes and potential treatment of anorexia in males, Meilleur said. "We need to explore the question of sexuality and muscularity," she said. "Because with women, at least, becoming thinner and thinner is the goal they're working towards. With men it's a paradox, because the thinner they become the less muscle they have -- so they don't get to their goal."

All of this means that "there is more going on here than we can see so far," Meilleur said.

Lona Sandon, a registered dietician and assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center at Dallas, stressed that "eating disorders are a psychiatric issue, not a food issue."

"But when it gets under way, a psycho-social struggle may end up manifesting in how a person eats or views their body," she noted. "And this kind of struggle, like body dysmorphia [poor body image], certainly does apply to both sexes."

"Perhaps the reason we don't think of young men as having body image issues is that the criteria we now have in place for diagnosing anorexia probably doesn't fit young men as well as it fits young women," Sandon said.

"Men may want to be 'ripped,' not emaciated. They're not necessarily going after very low body weight. But if we want to know for sure we need a big sample size of male patients, and some better quality research."

The study was published recently in Neuropsychiatry of Childhood and Adolescence.